534 resultados para cross-head speed
Resumo:
Poor compliance with speed limits is a serious safety concern at roadworks. While considerable research has been undertaken worldwide to understand drivers’ speeding behaviour at roadworks and to identify treatments for improving compliance with speed limits, little is known about the speeding behaviour of drivers at Australian roadworks and how their compliance rates with speed limits could be improved. This paper presents findings from two Queensland studies targeted at 1) examining drivers’ speed profiles at three long-term roadwork sites, and 2) understanding the effectiveness of speed control treatments at roadworks. The first study analysed driver speeds at various locations in the sites using a Tobit regression model. Results show that the probability of speeding was higher for light vehicles and their followers, for leaders of platoons with larger front gaps, during late afternoon and early morning, when higher proportions of surrounding vehicles were speeding, and at the upstream of work areas. The second study provided a comprehensive understanding of the effectiveness of various speed control treatments used at roadworks by undertaking a critical review of the literature. Results showed that enforcement has the greatest effects on reducing speeds among all treatments, while the roadwork signage and information-related treatments have small to moderate effects on speed reduction. Findings from the studies have potential for designing programs to effectively improve speed limit compliance at Australian roadworks.
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The late twentieth century witnessed the transformation of the global economy beyond the fixed geographic boundaries of the nation-state system to one dominated by financial centers, global markets, and transnational firms. In the two decades to 2011, cross-border philanthropy from OECD Development Assistance Committee (DAC) donor countries to the developing world grew from approximately USD 5 billion to USD 32 billion (OECD, n.d.),[1] with some estimates for 2011 as high as USD 59 billion (Center for Global Prosperity, 2013). This is only part of cross-border philanthropy, which also includes remittances from migrant communities, social-media-enabled global fundraising, and medical research collaborations.
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Travel speed is one of the most critical parameters for road safety; the evidence suggests that increased vehicle speed is associated with higher crash risk and injury severity. Both naturalistic and simulator studies have reported that drivers distracted by a mobile phone select a lower driving speed. Speed decrements have been argued to be a risk compensatory behaviour of distracted drivers. Nonetheless, the extent and circumstances of the speed change among distracted drivers are still not known very well. As such, the primary objective of this study was to investigate patterns of speed variation in relation to contextual factors and distraction. Using the CARRS-Q high-fidelity Advanced Driving Simulator, the speed selection behaviour of 32 drivers aged 18-26 years was examined in two phone conditions: baseline (no phone conversation) and handheld phone operation. The simulator driving route contained five different types of road traffic complexities, including one road section with a horizontal S curve, one horizontal S curve with adjacent traffic, one straight segment of suburban road without traffic, one straight segment of suburban road with traffic interactions, and one road segment in a city environment. Speed deviations from the posted speed limit were analysed using Ward’s Hierarchical Clustering method to identify the effects of road traffic environment and cognitive distraction. The speed deviations along curved road sections formed two different clusters for the two phone conditions, implying that distracted drivers adopt a different strategy for selecting driving speed in a complex driving situation. In particular, distracted drivers selected a lower speed while driving along a horizontal curve. The speed deviation along the city road segment and other straight road segments grouped into a different cluster, and the deviations were not significantly different across phone conditions, suggesting a negligible effect of distraction on speed selection along these road sections. Future research should focus on developing a risk compensation model to explain the relationship between road traffic complexity and distraction.
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This paper presents the validation of a manoeuvring model for a novel 127m-vehicle-passenger trimaran via full scale trials. The adopted structure of the model is based on a model previously proposed in the literature with some simplifications. The structure of the model is discussed. Then initial parameter estimates are computed, and the final set of parameters are obtained via adjustments based on engineering judgement and application of a genetic algorithm so as to match the data of the trials. The validity of the model is also assessed with data from a trial different from the one use for the parameter adjustment. The model shows good agreement with the trial data.
Resumo:
Speed is recognised as a key contributor to crash likelihood and severity, and to road safety performance in general. Its fundamental role has been recognised by making Safe Speeds one of the four pillars of the Safe System. In this context, impact speeds above which humans are likely to sustain fatal injuries have been accepted as a reference in many Safe System infrastructure policy and planning discussions. To date, there have been no proposed relationships for impact speeds above which humans are likely to sustain fatal or serious (severe) injury, a more relevant Safe System measure. A research project on Safe System intersection design required a critical review of published literature on the relationship between impact speed and probability of injury. This has led to a number of questions being raised about the origins, accuracy and appropriateness of the currently accepted impact speed–fatality probability relationships (Wramborg 2005) in many policy documents. The literature review identified alternative, more recent and more precise relationships derived from the US crash reconstruction databases (NASS/CDS). The paper proposes for discussion a set of alternative relationships between vehicle impact speed and probability of MAIS3+ (fatal and serious) injury for selected common crash types. Proposed Safe System critical impact speed values are also proposed for use in road infrastructure assessment. The paper presents the methodology and assumptions used in developing these relationships. It identifies further research needed to confirm and refine these relationships. Such relationships would form valuable inputs into future road safety policies in Australia and New Zealand.
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- Objective We sought to assess the effect of long-term exposure to ambient air pollution on the prevalence of self-reported health outcomes in Australian women. - Design Cross-sectional study - Setting and participants The geocoded residential addresses of 26 991 women across 3 age cohorts in the Australian Longitudinal Study on Women's Health between 2006 and 2011 were linked to nitrogen dioxide (NO2) exposure estimates from a land-use regression model. Annual average NO2 concentrations and residential proximity to roads were used as proxies of exposure to ambient air pollution. - Outcome measures Self-reported disease presence for diabetes mellitus, heart disease, hypertension, stroke, asthma, chronic obstructive pulmonary disease and self-reported symptoms of allergies, breathing difficulties, chest pain and palpitations. - Methods Disease prevalence was modelled by population-averaged Poisson regression models estimated by generalised estimating equations. Associations between symptoms and ambient air pollution were modelled by multilevel mixed logistic regression. Spatial clustering was accounted for at the postcode level. - Results No associations were observed between any of the outcome and exposure variables considered at the 1% significance level after adjusting for known risk factors and confounders. - Conclusions Long-term exposure to ambient air pollution was not associated with self-reported disease prevalence in Australian women. The observed results may have been due to exposure and outcome misclassification, lack of power to detect weak associations or an actual absence of associations with self-reported outcomes at the relatively low annual average air pollution exposure levels across Australia.
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Criminological theories of cross-national studies of homicide have underestimated the effects of quality governance of liberal democracy and region. Data sets from several sources are combined and a comprehensive model of homicide is proposed. Results of the spatial regression model, which controls for the effect of spatial autocorrelation, show that quality governance, human development, economic inequality, and ethnic heterogeneity are statistically significant in predicting homicide. In addition, regions of Latin America and non-Muslim Sub-Saharan Africa have significantly higher rates of homicides ceteris paribus while the effects of East Asian countries and Islamic societies are not statistically significant. These findings are consistent with the expectation of the new modernization and regional theories.
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The effects of life events, social support and the emotional well-being of partner on the emotional well-being of the mother during pregnancy was examined within the cultural contexts of Britain and Greece. It was proposed that social support, impact of life events and relationship of the mother with her partner would be affected by the different social structures of each culture and would influence emotional well-being. A sample of 200 Greek and 156 British mothers and their partners completed questionnaires which included a life event inventory, measure of social support and measure of emotional well-being (Crown-Crisp Experiential Index). Greek mothers were found to score significantly higher on measures of depression, anxiety and somaticism, experience more stressful life events (most relating to family issues) and report feeling less supported than British mothers. Life events, particularly those relating to family stresses were found to predict poor emotional well-being among Greek mothers. For British mothers, social support was the strongest predictor of emotional well-being. Findings were discussed in the light of differences in social structure and it was suggested that future research might focus on the disruption of established social support structures rather than the differences in availability of social support per se when considering maternal emotional well-being.
Resumo:
The effect of psychosocial factors on the emotional well-being of mothers following childbirth were examined within the cultural contexts of Britain and Greece. These mothers had already completed questionnaires during pregnancy and were contacted a second time in the postpartum period. At 4–6 weeks postpartum a sample of 165 Greek mothers and 101 British mothers and their partners completed the Edinburgh Postnatal Depression Scale. The relationship between mothers' EPDS scores and measures of emotional well-being in pregnancy (CCEI), social support, life events, fathers' EPDS score, and father's perception of change in partner was examined in each culture. No difference in the distribution of EPDS scores in each culture was found. Social support and life events were found to predict postnatal depression in both cultures. Additionally, in Greece, emotional well-being in pregnancy made a separate contribution to prediction. The major difference between the two cultures was in the relationship between mothers and their partners. Greek fathers were more emotionally and physically distanced from their partners during pregnancy, birth and early parenthood and perceived their partners as being more changed by the transition to parenthood. These differences were not reflected in differences in emotional well-being possibly because they accord with social expectation in each culture.
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Purpose: It is common for head and neck patients to be affected by time trend errors as a result of weight loss during a course of radiation treatment. The objective of this planning study was to investigate the impact of weight loss on Volumetric Modulated Arc Therapy (VMAT) as well as Intensity modulated radiation therapy (IMRT) for locally advanced head and neck cancer using automatic co-registration of the CBCT. Methods and Materials: A retrospective analysis of previously treated IMRT plans for 10 patients with locally advanced head and neck cancer patients was done. A VMAT plan was also produced for all patients. We calculated the dose–volume histograms (DVH) indices for spinal cord planning at risk volumes (PRVs), the brainstem PRVs (SC+0.5cm and BS+0.5cm, respectively) as well as mean dose to the parotid glands. Results: The results show that the mean difference in dose to the SC+0.5cm was 1.03% and 1.27% for the IMRT and VMAT plans, respectively. As for dose to the BS+0.5, the percentage difference was 0.63% for the IMRT plans and 0.61% for the VMAT plans. The analysis of the parotid gland doses shows that the percentage change in mean dose to left parotid was -8.0% whereas that of the right parotid was -6.4% for the IMRT treatment plans. In the VMAT plans, the percentages change for the left and the right parotid glands were -6.6% and -6.7% respectively. Conclusions: This study shows a clinically significant impact of weight loss on DVH indices analysed in head and neck organs at risk. It highlights the importance of adaptive radiotherapy in head and neck patients if organ at risk sparing is to be maintained.
Resumo:
A prospective study was conducted of fathers' transition to parenthood from mid-pregnancy to 6 weeks postpartum. The subjects were 198 fathers from Greece (Athens) and 142 from Britain (Bristol). Social class, age and parity distributions were similar between the two populations. The culture and social structure experienced by each varied widely, however, and was a focus of interest. Two major themes in fatherhood across the two populations were explored: first, the father's instrumental role in provision of emotional and practical support to his partner and care for his child; and second the father's emotional reaction to his partner's pregnancy, the birth of his child and early parenthood. In both cultures fathers reported that they took an active instrumental role in supporting their partner and in participating in childcare. Markedly more British fathers attended the delivery. There were no overall differences in the degree to which fathers participated in childcare though the nature of this participation varied. British fathers more commonly took on housework duties. During their partner's pregnancy Greek fathers experienced significantly higher malaise than their British counterparts and also reported feeling that they had less social support. Common to many fathers in both cultures during this time were fears that their partner might change or be damaged by the pregnancy. After the birth, there was no difference in emotional well-being between the Greek and British fathers. Reactions to fatherhood and enjoyment of the child were similar for the two cultures also. Patterns of correlation between variables both within and across the antenatal and postnatal time periods were, for the most part, similar for the two cultures. Social support, however, was found to relate to father's emotional and instrumental reaction to parenthood only in the case of the British sample. Findings are discussed in terms of each culture's point on the continuum of social change.
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Objectives: Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous tumour type which necessitates multiple invitro models to attain an appreciation of its multiple subtypes. The phenomenon of epithelial-mesenchymal transition (EMT) isimportant to the development of a metastatic cancer cell phenotype being relevant to the ability of cancer cells to intravasate intovasculature and to invade tissues. The role of EMT in human papilloma virus (HPV) positive HNSCC is not well understood. Thispaper aims to characterize seven HNSCC cell lines (FaDu, SCC-25, SCC-15, CAL27, RPMI2650) including two new HPV-16positive HNSCC cell lines (UD-SCC2, 93-VU-147T) for their epithelial and mesenchymal properties. Materials and methods: A panel of HNSCC cell lines from multiple head and neck anatomical sites were profiled for basalexpression of epithelial and mesenchymal characteristics at mRNA, protein and functional levels (proliferative, migratory andinvasive properties). Furthermore, 3D spheroid forming capabilities were investigated. Results: We found that the HPV-16 positive cell line, in particular UD-SCC2 demonstrated a more invasive and mesenchymalphenotype at the molecular and functional levels suggesting HPV infection may mediate some of these cellular properties.Moreover, HPV-negative cell lines were not strictly epithelial presenting with a dynamic range of expression. Conclusions: This study presents the molecular and phenotypic diversity of HNSCC cell lines. It highlights the need formore studies in this field and a scoring system where HNSCC cell lines are ranked according to their respective epithelial andmesenchymal nature. This data will be useful to anyone modelling HNSCC behaviour, providing a molecular context which willenable them to decipher cell phenotypes and to develop therapies which block EMT progression.
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Head and neck cancer patients often present with advanced metastatic disease resulting in a poor 5-year survival. Therefore, there is a need for non-invasive diagnostic tools that could complement conventional imaging to inform clinicians of patient outcomes and treatment responses. A liquid biopsy addresses this unmet clinical need; a simple peripheral blood draw could provide information about the disseminated disease in terms of circulating tumor cells and circulating tumor DNA. Moreover, detectable tumor DNA in the saliva of head and neck cancer patients could signify the early signs of the disease and present an opportunity for clinical intervention. This review provides an overview of the current literature with regard to the feasibility of such a test in the head and neck cancer field and highlights the need for such a test.
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Purpose This study evaluated the impact of a daily and weekly image-guided radiotherapy protocols in reducing setup errors and setting of appropriate margins in head and neck cancer patients. Materials and methods Interfraction and systematic shifts for the hypothetical day 1–3 plus weekly imaging were extrapolated from daily imaging data from 31 patients (964 cone beam computed tomography (CBCT) scans). In addition, residual setup errors were calculated by taking the average shifts in each direction for each patient based on the first three shifts and were presumed to represent systematic setup error. The clinical target volume (CTV) to planning target volume (PTV) margins were calculated using van Herk formula and analysed for each protocol. Results The mean interfraction shifts for daily imaging were 0·8, 0·3 and 0·5 mm in the S-I (superior-inferior), L-R (left-right) and A-P (anterior-posterior) direction, respectively. On the other hand the mean shifts for day 1–3 plus weekly imaging were 0·9, 1·8 and 0·5 mm in the S-I, L-R and A-P direction, respectively. The mean day 1–3 residual shifts were 1·5, 2·1 and 0·7 mm in the S-I, L-R and A-P direction, respectively. No significant difference was found in the mean setup error for the daily and hypothetical day 1–3 plus weekly protocol. However, the calculated CTV to PTV margins for the daily interfraction imaging data were 1·6, 3·8 and 1·4 mm in the S-I, L-R and A-P directions, respectively. Hypothetical day 1–3 plus weekly resulted in CTV–PTV margins of 5, 4·2 and 5 mm in the S-I, L-R and A-P direction. Conclusions The results of this study show that a daily CBCT protocol reduces setup errors and allows setup margin reduction in head and neck radiotherapy compared to a weekly imaging protocol.
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This new work provides a comprehensive and theoretically rich discussion of the law on cross-border insolvency. It engages with several current multi-billion dollar insolvencies such as those of Nortel Networks and Lehman Brothers to provide the reader with state of the art knowledge of the complex problems posed by transnational insolvency. As the number of transnational insolvencies grows due to prevailing economic conditions, practitioners are increasingly required to navigate the mass of legal rules applicable to cross-border insolvency situations. The associated challenges are heightened by the diversity of legal structures employed by modern business entities and a patchwork of costly, inefficient, and unpredictable national legal rules. The response has been a proliferation of international legal instruments such as the UNCITRAL Model Law and the the EU Insolvency Regulation, supplemented by judicial practice, adding further layers of complexity. Writing from an Australian perspective, the authors analyse this network of legal rules and subsequent case law. In addition, they explain the theoretical underpinnings of these rules in an accessible manner to build a solid foundation for practice, facilitate advanced reasoning, and enable the development of sophisticated arguments for law reform. Comparative case law from jurisdictions such as the United States and United Kingdom is also included. This book is highly relevant to insolvency practitioners faced with the recovery of assets located in different jurisdictions, transactional lawyers for whom knowledge of potential insolvency pitfalls is essential, and academics. It is invaluable for students at both undergraduate and postgraduate level seeking a sound understanding of this challenging area of law.